1. Field of the Invention
This invention relates to a repeating unit testing system for a repeating unit such as a router which repeats communication between a plurality of apparatus and a communication apparatus as well as a communication method, and more particularly to tests of the line connection time and the total packet number between a repeating unit and a communication network such as a public line.
2. Description of the Related Art
As a result of development of the communication technique, a large scale user takes a form wherein local area networks (local area network is hereinafter referred to as LAN) at various positions in the whole country are connected to each other by a wide area network. In this form, such a connection form of a first LAN--first router (repeating unit)--WAN such as an INS network--second router (repeating unit)--second LAN is taken. In a connection form of such a type as just described, a first LAN terminal accommodated in the first LAN sets an address (for example, an IP address) of a second LAN terminal accommodated in the second LAN to packets and transmits the packets to the first router. The first router refers to its routing table to determine an output port for the packets from the IP address and transmits the packets from the port to the second router through the INS network.
The second router refers to its routing table to determine an output port for the packets from the IP address and transmits the packets to the second LAN terminal. The second LAN terminal receives the packets. When such packets are transmitted using a public network such as an INS network, it is charged by a time rate or a meter rate. According to the time rate, the charge depends upon a connection time of the INS network, and according to the meter rate, the charge depends upon the number of transmitted packets. Accordingly, when the first router connects a line to the INS network and transmits packets, if excessive time is required for the line connection or a surplus packet is transmitted to the INS network, then an excessive amount of money is charged, which is inconvenient for the user. In order to eliminate such a situation, a test is required to confirm that the line connection time between each router and the INS network is normal and that the total transmission packet number is normal.
Conventionally, the line connection time or the packet number is confirmed by outputting information (log information) recorded by a router to an outputting apparatus such as a printer so as to allow manual confirmation or by developing a warning if the connection time or the packet number exceeds a threshold value. Besides, such confirmation relies upon actual connection to and communication with an INS network. However, conventionally a correct value to be used for reference for confirmation of whether or not a result of a test is normal must be calculated by comparison with a log by a human being, and this is disadvantageous in that much time is required for the calculation and besides the reliability is low.